1. Field of the Invention
This invention relates to a web feeding apparatus in which a web such as a microfilm is fed from a supply portion to a take-up portion and taken up onto the reel of the take-up portion.
2. Description of the Prior Art
When a web such as printing paper or film contained in the form of a roll in a supply portion such as a cartridge or a supply reel is to be taken up onto a take-up reel, the take-up reel is rotatively driven by a motor to thereby feed the web. In a search device for finding out particular information from a film having a great deal of information recorded thereon, the film is taken up onto the take-up reel or rewound onto the supply portion at a high speed. The film used with such a search device is provided, for example, with a frame mark on a side edge of the film correspondingly to the frames of the film, and the feeding of the film is controlled by detecting such mark. The vicinity of the terminal end of the film is usually a blank portion called the trailer portion, the terminal end of which is usually secured to the reel of the supply portion. Accordingly, when a desired frame in the film is to be searched for, it is necessary to rewind or stop the film after the last frame of the film has been detected, but if the film is fed at a high speed up to the terminal end thereof on the supply side, a strong impact force may be applied to the terminal end of the film secured to the supply portion to thereby damage mechanical parts or break the film. Thus, heretofore, to detect the terminal end of the film, it has been practised to provide an end mark in the vicinity of the terminal end of the film, namely, on the trailer portion of the film, and to stop the film in response to the detection thereof, but this method required a mark to be specially provided on the film and the labor involved therein is heavy and the working property is poor, and moreover, such method is not applicable to a film having no end mark provided thereon.